Pump



Aug. 9, 1960 5, NEELY 2,948,227

' PUMP Filed NOV. 19, 1958 I IN V EN TOR. W5 BY FIG 5 if? I @2231,

. f' Patented Aug. 9, 1960 United States invention is a rotary pumphaving a pump hens-- mg with end ,walls whose axial separation variesfrom a at one side to a maximum at the'opposite side of the axis ofrotation- The impeller'has axially projectingflexible, blades confinedbetween the end walls. At low speeds, the blades are flexed axially tovary the volume between adjacent blades and produce positivedisplacement'pumping. 'At higher speeds, the blades are flexed by thefluid pressure away from contact with the housing end walls and acentrifugal pumping action 'is obtained.

In the drawings, Fig. 1 is an end view of an impeller; Fig. 2 is asection of line 22 of Fig. 1; Fig. 3 is an end view of a pump housing;Fig. 4 is a section of line 4-4 of'Fig. ,3; Fig. 5 is a diagrammaticperspective illustrating the position of the impeller blades during lowspeed pumping; Fig. 6 is a view similar to Fig. 2 but with the bladesofunequal axial projection on opposite sides of the center disc; andFig. 7 is an edge view. of an imthe impeller from the suction side andin a similar manrotate from point 22 to point 23 in a clockwisedirection, the blades are continually expanding axially therebyincreasing the volume of the space between adjacent blades and creatinga suction at the inlet 20. As the impeller rotates-from .point 23 topoint 22, the blades are confi tinually being compressedaxially therebyreducing space between adjacent blades and forcing liquid out the outlet21; It will be noted that on the pressure side of point 22 there is apair of blades designated by the numerals 24 and which at all times sealthe pressure side of ner on the suction side of point 22 blades 25 and26 seal the liquid pressure from the inlets 20. As the impeller rotatesfrom the position illustrated in Fig. 3, the space between the twoblades 24 and 25 continues to decrease until the blade 25" reaches point22 and any pressure built up between the blades is relieved by flexingof the blade 24. Asthe blade 25 passes point 22, the blade 26-sta1'ts topass over the suction inlet 20 and the suction created by the gradualincrease of the space between the blades 25 and 26 draws liquid into theinlets 20. Because of the blades 24, 25 and 26, it is not possible atany time for liquid to flow from the pressure side of illustrated in theperspective view of Fig. 5.

peller having blades of configuration for improved stress distribution.

The pump impeller has a metal hub 1 fixed to a drive shaft 2 and bondedto the center of a rubber disc 3 carrying'integral axially projectingrubber blades 4 on opposite surfaces. The shaft 2 is journaled inopposite end walls 5 and 6 of a, Pump housing 7 and is provided withsuitable seals 8. Surrounding the shaft, 2 are axially projecting rubbersleeves 9 and 10 integral with the impeller which fit in recesses 11 and12 of the end walls 5 and 6. The sleeves 9 and 1 0 rotate with theimpeller and provide seals which increase in effectiveness duringrotation due to the effect ofcentrifugal force which causes a slightexpansion of thesleeves. The sealing action of thesleeves 9 and 10 isadequate for most applications so that the seals 8 may be omitted. :Thehousing end walls Sand 6 have integral tubular projections 13 and 14which are received in slots or notches 15 and 16 in the blades 4 andwhich provide flexible outer sections 17 and 18 on the blades which arefree to flex without stressing the disc 3 or the bonded connection tothe hub 1. The blades 4 have the same diameter as the disc 3 and makesliding engagement with the outer peripheral wall 19 of the pump housingand also with the outer surfaces of the projections 13 and 14 which maybe considered as the inner peripheral wall of the pump housing. Theparts so far described are all concentric with the pump shaft 2.

The pump housing has two inlet connections 20, respectively on the upperand lower sides of the disc 3, and has two outlet connections 21 whichare on the upper and lower sides of the disc. As shown more clearly inFig. 4, the end walls '5 and 6 of the pump housing lie in planes whichare inclined to each other and to the axis of the pump shaft.Accordingly, as the impeller rotates at low speeds, the blades 4 arecompelled to flex axially. The point of separation between the end walls5 and 6 of the pump housing is designated by the numeral 22 and thepoint of separation is designated by the numeral 23. As the impellerblades point 22 to the inlets 20.

The flexing of the impeller blades 4 is diagrammatically In this figure,unstressed positions of the blades is designated by the numeral 27 andthe planes of the end walls 5 and 6 of the pump housing are designatedby the numerals 28 and 29. Fig. 5 shows the position of the blades atslow speed rotation of the impeller. At higher speeds,

the liquid pressure on the leading face of the blades a the pump forpumping liquids from two separate sources.

Whenthe disc issymmetrically located with blades of equal, projection onopposite sides, the pumping cavities will have equal capacity. By havingthe blades 4a on one side of the disc 3 of greater axial projection thanblades 4b on the other side of the disc as shown in Fig. 6, the pumpingcavities will have unequal capacity. Inequality of pumping capacity mayalso be obtained by having one of the end walls of the pump housing at adifferent inclination than the other.

By having the blades on opposite sides of the center disc 3, axialbending forces on the blades are balanced against each other. Radialbearing loads are eliminated because the blades are concentric with thepump shaft. Many of the stresses present in pumps with radiallydefleeting blades are accordingly eliminated. The design permits veryuniform stressing of the impeller blades which means that withoutexceeding the operating stress, the amount of flexing of the blades canbe increased with the resultant increase in pump capacity which isdirectly proportional to the amount of flexing of the blades. The bladeconfiguration shown at 30 in Fig. 7 is preferable because the section 31subject to the greatest bending moment has the greatest cross section.

It is not necessary that the disc 3 be circular so as to divide the pumphousing into two separate pumping cavities. The disc can be cut awaybetween adjacent blades, for example, by notches extending inward fromthe periphery of the disc so there will be only a single pumping cavitybetween adjacent blades. With the disc cut away, the same kind ofpumping action will be obtained as the blades are axially flexed but, ofcourse,

fluid can be pumped only from a single source because the disc will nolonger block free fluid communication between its upper and lower sides.Since the disc acts as part of the structural support for the blades, itis advantageous to keep the part of the disc immediately adjacent theblades and hub as a structural part.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A rotary pump having a housing with end Walls having an axialseparation which varies angularly about the axis of the pump from amaximum to a minimum and back to a maximum, a rotary impeller having ahub at the center, a tubular sleeve of flexible material united to theimpeller concentric with and projecting axially from the hub, aplurality of angularly spaced flexible blades carried by the hub andbridging the space between the end walls and being deflected axially tochange the volume between adjacent blades as the impeller is rotated,said blades having notches radially outside and adjacent said sleeve,said housing having a tubular projection radially outside and telescopedover and making sealing engagement with said sleeve and complementary toand received in said notches, and an inlet on the side of the housing inwhich the volume between adjacent blades is increasing and an outlet onthe side of the housing .in which the volume between adjacent blades isdecreasing as the impeller is rotated.

2. A rotary pump having a housing with end walls having an axialseparation which varies angularly about the axis of the pump from amaximum to a minimum and back to a maximum, and a rotary impeller havinga hub at the center carrying two sets of angularly spaced flexibleblades extending between the hub and the pe riphery of the impeller andwith each set of blades projecting axially into engagement with adifferent end wall, each blade having an axially extending notch at itsinner end, said housing having axially inward extending tubularprojections complementary to said notches and extending from oppositeends of the housing into said notches, said impeller having tubularsleeves radially inside said tubular projections and projecting axiallyoutward from the impeller and having outer ends telescoped in sealingengagement into said tubular projections of the housing, and said bladesbridging the space between the end walls and being deflected axially tochange the volume between adjacent blades as the impeller is rotated,and an inlet on the side of the housing in which the volume betweenadjacent blades is increasing and an outlet on the side of the housingin which the volume between adjacent blades is decreasing as theimpeller is rotated.

3. A rotary pump having a housing with end walls with an axialseparation a minimum at one point around the circumference of thehousing, a rotary impeller having a hub at the center between the endwalls and carrying two sets of angularly spaced flexible blades, eachset respectively projecting axially into engagement with a different endwall, said blades bridging the space between the end walls and beingdeflected axially to change the volume between adjacent blades as theimpeller is rotated, said blades having at their inner ends notchesextending axially inward from the end walls of the housing, said housinghaving axially inward extending tubular projections complementary to thenotches and extending from opposite ends of the housing into saidnotches, said im: peller having tubular sleeves radially inside saidtubular projections and projecting axially outward from the impeller andhaving outer ends telescoped in sealing engagement into said tubularprojections of the housing, and an inlet communicating with the housingon the side of said point in which the volume between adjacent blades isincreasing as the impeller is rotated past said point and an outletcommunicating with the housing on the side of said point in which thevolume between adjacent blades is decreasing as the impeller is rotatedpast said point.

4. A rotary pump having a housing, a rotary impeller having a pluralityof angularly spaced flexible blades with a sliding fit in the housing,said housing having a region of minimum axial length whereby the bladesare deflected axially to change the volume between adjacent blades asthe impeller is rotated past said region, said impeller have ing at itscenter flexible sleeves with free ends projecting axially in oppositedirections, said housing having tubular projections radially outside andtelescoped over said sleeves and making sealing engagement therewith,said blades having'notches radially outside said sleeves andcomplementary to and receiving said tubular projections, and an inletcommunicating with the space between the blades on the side ofsaidregion in which the volume between adjacent blades is increasing as theimpeller is rotated past said region and an outlet communicating withthe space between the blades on the side of said region in which thevolume between adjacent blades is decreasing as the impeller is rotatedpast said region.

References Cited in the file of this patent UNITED STATES PATENTS2,533,399 Sad-let et a1 Dec. 12, 1950' 2,542,240 Fernstrum Feb. 20, 1951 2,542,268 Weyer Feb. 20, 1951 2,573,819 Weyer Nov. 6, 1951 2,605,715Brant Aug, 5, 1952 2,649,052 Weyer Aug. 18, 1953 2,711,136 1 Arnold June21, 1955 2,734,457 Fernstrum Feb. 14, 1956 2,853,021 Doble Sept. '23,1958 2,858,769 Doble Nov. 4, 1958 2,881,710 McLean Apr. 14, 1959

